Download Name Date AP Biology – Metabolism and Enzymes Review When a

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AP Biology – Metabolism and Enzymes Review
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1. When a cell breaks down glucose, only about 34% of the energy is captured in ATP
molecules. The remaining 66% of the energy is
a. used to increase the order necessary for life to exist.
b. lost as heat, in accordance with the second law of thermodynamics.
c. used to increase the entropy of the system by converting kinetic energy into
potential energy
d. stored in starch or glycogen for later use in the cell.
e. released when the ATO molecules are hydrolyzed.
2. When glucose and O2 are converted to CO2 and H2O, changes in total energy, entropy,
and free energy are correctly represented by
a. –ΔH, –ΔS, –ΔG
c. –ΔH, +ΔS, +ΔG
e. +ΔH, –ΔS, –ΔG
b. –ΔH, +ΔS, –ΔG
d. +ΔH, +ΔS, +ΔG
3. A negative ΔG means that
a. the quantity G of energy is available to do work.
b. the reaction is spontaneous.
c. the reactants have more free energy than the products.
d. the reaction is exergonic.
e. All of the above are true.
4. An enzyme raises which of the following parameters?
a. ΔG
c. the free energy of activation
e. the equilibrium of the reaction
b. ΔH
d. the speed of the reaction.
5. At equilibrium,
a. no enzymes are functioning.
b. free energy is decreasing.
c. the forward and the backward reactions have stopped.
d. ΔG = 0
e. All of the above are true.
6. An endergonic reaction could be described as one that
a. proceeds spontaneously with the addition of activation energy.
b. produces products with more free energy than the reactants.
c. is not able to be catalyzed by enzymes.
d. releases energy.
e. produces ATP for energy coupling.
7. The formation of ATP from ADP and inorganic phosphate
a. is an exergonic reaction.
b. transfers the phosphate to an intermediate that becomes more reactive.
c. produces an unstable energy compound that can drive cellular work.
d. involves hydrolysis of a phosphate bond.
e. All of the above are true.
8. What is meant by an induced fit?
a. The binding of the substrate is an energy-requiring process.
b. A competitive inhibitor can outcompete the substrate for the active site.
c. The active site creates a microenvironment ideal for the reaction.
d. The binding of the substrate changes the shape of the active site, which can stress
or bend substrate bonds.
e. The binding of an activator to an allosteric sites induces a more active form of the
subunits of the enzymes.
9. When substance A was added to the enzyme reaction, product formation decreased.
The addition of more substrate did not increase product formation. From this, we can
conclude that substance A could be
a. product molecules.
c. an allosteric enzyme.
e. a noncompetitive inhibitor.
b. a cofactor.
d. a competitive inhibitor.
10. Which of the following is most directly responsible for the specificity of a protein
enzyme?
a. Its primary structure.
d. the R groups of the amino acids in its active site
b. Its secondary and tertiary structure. e. its cofactors.
c. The shape and characteristics of its allosteric site
11. In cooperativity,
a. A cellular organelle contains all the enzymes needed for a metabolic pathway.
b. A product of a pathway serves as a competitive inhibitor of an enzyme early in the
pathway.
c. A molecule bound to the active site of one subunit of an enzyme affects the active
site of other subunits.
d. The allosteric site is filled with an activator molecule.
e. The product of one reaction serves as the substrate for the next reaction in intricately
ordered metabolic pathways.
12. In the metabolic pathway A B  C  D  E, what effect would molecule E likely have
on the enzyme that catalyzes A  B?
a. Allosteric inhibitor
c. competitive inhibitor
e. coenzyme.
b. Allosteric activator
d. feedback activator
13. In an experiment, changing the pH from 7 to 6 resulted in an increase in product
formation. From this, we can conclude that
a. the enzyme became saturated at pH 6.
b. the enzyme’s optimal pH is 6.
c. this enzyme works best at a neutral pH.
d. the temperature must have increased when the pH was changed to 6.
e. the enzyme was in a more active shape at pH 6.